Long tunnels of many kilometres are likely to pass through a range of geologies which may cause problems. The present invention seeks to overcome the disadvantages of the prior art by: drilling a first bore 10 along a first predetermined path, the first bore having a length of at least 25 m; drilling a plurality of second bores 20 along respective second predetermined paths, each substantially parallel to the first predetermined path in order to define a substantially prism-shape region therebetween; and excavating material within the substantially prism-shape region to form a tunnel. In this way, data from drilling the first bore 10 and the plurality of second bores 20 can be recorded and used to inform operators as to the types of material through which they will be excavating. Thus, a more complete view of the underlying geology can be achieved before beginning excavations.

Provide is a method for real-time deviation monitoring of miniature pipe-roofing jacking pipes of spiral soil-discharging. The method includes: welding a measurement auxiliary pipe to an outer wall of a pipe-roofing steel pipe, providing a laser pen inside a front end of the measurement auxiliary pipe, and the laser pen emits a beam propagating from the front end to a rear end of the measurement auxiliary pipe. After installation, a male lock buckle and a female lock buckle are symmetrically welded onto the pipe-roofing steel pipe, and form an integrated structure with the pipe-roofing steel pipe. A measurement plate is fixedly mounted on a housing of a pipe-roofing drilling machine. During jacking, a change of a position of the beam on the measurement plate is observed to determine a deviation of a drill bit of the pipe-roofing drilling machine and the pipe-roofing steel pipe in real-time.

The present disclosure relates to a construction method and system for roof sealing and foundation strengthening of a crossing project in a high-density urban area. The method includes: penetrating drainage conduits into a first depth of a vertical position under a bottom of a solidification position layer on both sides of a construction site, and drawing a liquid level to a second depth under the bottom of the solidification position layer by using the drainage conduits; performing drilling from both sides of the construction site to a solidification position, and performing reinforcement treatment on the drilled hole to form a grouting hole; and penetrating grouting pipes from a wellhead into the grouting hole such that grouting positions of the grouting pipes are positioned at a location of a weakened layer above a tunnel, and a formation to complete construction of roof sealing and foundation strengthening.

Jet grouting involves injecting grout into geological material to improve its quality; however, use of jet grouting is limited to situations in which the injection systems can be positioned relatively close to the region to be improved. This can be impractical (for example in heavily built up areas, rough terrain or beneath the seabed) or inconvenient (for example where closing a tunnel would be required). The present invention enables deployment equipment 41 to be passed down a bore in order to deploy material and/or equipment through a hole in the lining of a bore 43 into the underlying geology. In this way, underground assets may be repaired from a location external to the asset, allowing repair in situations where it would be impossible or cost-prohibitive to do so with conventional ground treatment techniques.

A method for recovery of residual coal pillars by freezing accumulated water in room-and-pillar mining areas is provided. A feasibility of repeated mining of residual coal pillars in room-and-pillar goafs is distinguished based on production data and exploration data of a mine. An accumulated water in the room-and-pillar mining areas is frozen to replace a paste filling material, which envelopes collapse roofs and gangues in the room-and-pillar goaf as a whole. The room-and-pillar goaf is filled with a frozen ice body. Roadways and mining faces are arranged in the frozen ice body. Coal cutter cuts the residual coal pillars and the frozen ice body. With the advancing of the mining face, the residual coal pillars are gradually recovered and melted water after the cutting is pumped out.

A static crushing directional anchor withdrawal method at the end of a large-mining-height working face is provided. The method includes the following steps: designing key parameters of boreholes for static crushing, including a borehole position, a spacing between boreholes, a borehole depth, and a borehole diameter at the end of a working face; then determining parameters of a static crushing agent grouting technology device for the construction of a static crushing process; and carrying out an anchor withdrawal operation at the end. The method can solve the problem of difficult roof anchor withdrawal at the end of a working face, is beneficial to shortening the hanging roof distance of the working face, preventing the sudden caving of hanging roofs at the upper and lower corners of the working face and the potential safety hazard caused by gas overrun, and guaranteeing the normal use of the mining roadway.